Apparatus for piecing a thread in an open-end spinning unit

ABSTRACT

Apparatus for piecing a thread in an open-end spinning unit having a spinning rotor with a ring of opened-up fibers including opening means having comb means for combing out the thread end and a device for returning the thread end into the spinning rotor after combing thereof by the comb. Preferred embodiments of the invention include combs mounted on rotor wheels, as well as combs disposed on planar members. Preferred embodiments include backing members for backing the thread during combing operation, with embodiments including pairs of combing members disposed at opposite sides of the thread to comb and backup the same simultaneously. Clamping devices are provided for clamping the thread at positions on opposite side of the combing devices and for pulling the thread apart after it has been weakened by the combing operation. In other preferred embodiments, separate severing or cutting devices are provided for cutting off the extreme end portion of the thread end after the combing operation.

United States Patent [191 Stahlecker et a1.

1 Dec. 9, 1975 APPARATUS FOR PIECING A THREAD IN AN OPEN-END SPINNINGUNIT [76] Inventors: Fritz Stahlecker, Josef-Neidhart-Str. 18, D 7341Bad Ueberkingen; Hans Stahlecker, Haldenstrasse 20, D 7334 Suessen, bothof Germany 22 Filed: on. 10, 1974 21 Appl. No.: 513,776

[30] Foreign Application Priority Data Oct. 10, 1973 Germany 2350842[52] US. Cl. 57/34 R; 57/58.89 [51] Int. Cl. D01H 7/00; D01H 1/12;D0lI-l 15/00 [58] Field of Search 57/22, 34 R, 34 TT, 58.89,

[56] References Cited UNITED STATES PATENTS 2,515,172 7/1950 Abbott57/159 3,163,976 l/1965 Juillard 57/58.89 3,425,205 2/1969 Landwehrkampet a1 52/58.89 3,492,804 2/1970 Landwehrkamp et al..... 57/58.89 X3,626,440 12/1971 Harmon 57/34 R 3,722,198 3/1973 Gotzfried 57/58.89

Primary ExaminerDonald E. Watkins Attorney, Agent, or FirmCraig &Antonelli [57] ABSTRACT Apparatus for piecing a thread in an open-endspinning unit having a spinning rotor with a ring of opened-up fibersincluding opening means having comb means for combing out the thread endand a device for returning the thread end into the spinning rotor aftercombing thereof by the comb. Preferred embodiments of the inventioninclude combs mounted on rotor wheels, as well as combs disposed onplanar members. Preferred embodiments include backing members forbacking the thread during combing operation, with embodiments includingpairs of combing members disposed at opposite sides of the thread tocomb and backup the same simultaneously. Clamping devices are providedfor clamping the thread at positions on opposite side of the combingdevices and for pulling the thread apart after it has been weakened bythe combing operation. In other preferred embodiments, separate severingor cutting devices are provided for cuttin'g off the extreme end portionof the thread end after the combing operation.

25 Claims, 4 Drawing Figures US. Patent Dec. 9 1975 APPARATUS FORPIECING A THREAD IN AN OPEN-END SPINNING UNIT BACKGROUND AND SUMMARY OFTHE INVENTION This invention relates to an apparatus for piecing athread in an open-end spinning unit with a device for returning a threadend into a spinning rotor containing a ring of opened-up fibers. Relatedapplications of applicants to be filed herewith, having similar titlesas the present application, and based on US. application Ser. Nos.513,775 and 513,849, both filed on even date herewith, are incorporatedherein to the extent necessary for a complete understanding of thepresent invention.

A piecing of a thread is necessary when a machine is put back intooperation after a standstill, as well as any time the thread breaks.Devices have been contemplated for this purpose, by means of which athread end is returned into the spinning rotor, attached to the fiberring deposited at that location, and then taken off again. In thisoperation, certain conditions must be exactly maintained, such as, forexample, the instant of attachment, the length of the returned thread,and the speed of returning and take-off in order to obtain asatisfactory piecing effect. Yet, it has been unavoidable heretoforeunder practical conditions that the yarn quality is reduced at thepiecing points, due to the fact that thickened zones are produced in theyarn, on the one hand, and the tear strength is greatly reduced in thezone of the piecing points, on the other hand. Therefore, is has beencontemplated to eliminate these yarn defects by a rewinding processwherein the piecing locations are cut out and replaced by knots.However, this rewinding step requires increased expenditure in machineryand time, making it difficult to conduct the process economically.

The present invention is based on the problem of providing an apparatusof the type mentioned hereinabove, making it possible to effect animproved piecing step while avoiding a thickening of the yarn as well asany reduction in tear strength. The invention contemplates providing anopening device for the thread end which contains means for combing outthe thread end. Thereby, the thread end is opened up, prior to beingreturned into the spinning rotor and before it is attached to the ringof fibers deposited at that location, to such an extent that itscondition corresponds approximately to the condition of the fiber ring.Consequently, a satisfactory attachment is made possible without athickening of the yarn or a reduction in tear strength.

In a structurally advantageous embodiment of the invention, a clampingmeans is provided for the thread, followed by a combing out devicemovable toward the thread end. In this connection, it is advantageous toprovide a device which cuts the thread to length after the clampingmeans and in the close proximity after the combing out device. Thereby,the thread length necessary for the piecing step is determined, on theone hand, while it is ensured, on the other hand, that the thread end isin the zone of the opening device. For the same purpose, in anotherembodiment of the invention, clamping zones are arranged on both sidesof the combing or carding means, the outer one of these zones, whichfaces away from a windup spool, being movable in the longitudinaldirection of the thread. During carding or combing, a weakening of thethread is produced in this zone, which then will result in rupturing ofthe thread at this point, if the outer clamping zone is moved in thelongitudinal direction of the thread, for example by spring force or thelike.

These and further objects, features and advantages of the presentinvention will become more apparent from the following description whentaken in connection with the accompanying drawings, which show, forpurposes of illustration only, several embodiments in accordance withthe present invention.

BRIEF DESCRIPTION OF THE DRAWINGS preferred embodiment according to thepresent invention of apparatus for piecing a thread end;

FIG. 5 is a side schematic view which shows a fifth preferred embodimentaccording to the present invention of apparatus for piecing a threadend.

DETAILED DESCRIPTION OF THE DRAWINGS FIG. 1 shows only a spinning rotor2 of an open-end spinning unit 1 wherein, with the aid of feeding andopening means, not shown, a ring 3 of opened up fibers is continuouslydeposited. Via a yarn takeoff duct 4, the ring 3 is withdrawn as acontinuously spun thread. This thread is wound onto a windup spool 8which, during normal operation, rests on a winding roll 6 by which it isdriven. To mend a thread break, a thread end of the thread 5 is returnedvia the yarn takeoff duct 4 into the spinning rotor 2, attached to thering 3 of opened up fibers located therein, and then again withdrawn.The return and withdrawing motions required for this procedure arecontrolled, for example, by an auxiliary winding roll 7 on which thewindup spool 8 rests during the piecing step. Before the thread end isfed to the yarn takeoff duct 4, by way of which it is then sucked intothe spinning rotor 2 with the aid of a vacuum, it is opened up by anopening device 10 in order to adapt its condition to the condition ofthe ring 3 of opened up fibers.

The opening means 10 illustrated schematically in FIG. 1 contains aclamping zone 11 into which the thread 5 is laid manually ormechanically. A combing out or carding roll 12 follows the clamping zone11, this roll being provided with a tooth-like or pin-type trim alongits periphery. The combining out roll 12 is driven about an axisdisposed at right angles to the longitudinal direction of the thread.The direction of rotation is chosen so that the trim of the carding roll12 combs out the thread end in a direction away from the clamping zone11. Directly following the carding roll 12, a device 13 is arrangedwhich cuts the thread 5 to length and fixes the thread end. Theremaining piece of thread 144 (FIG. 2) can be removed, for example bysuction with the aid of a suction nozzle 9. A blowing nozzle 14 isdisposed in opposition to the carding roll 12 on the other side of thethread end; this nozzle urges the thread end into the area of the trimof the combing out roll, so that an effective carding action is obtainedwhich is furthermore supported by the air jet.

The clamping zone or station 11 is arranged on a swivel arm 16 pivotableabout an axle 15. This arm 16 is swiveled so that the opened up threadend is offered to the mouth of the yarn takeoff duct 4, via which thethread end is then sucked into the spinning rotor 2 (see the position11, 16' shown in dot-dash lines).

The embodiment of FIG. 2 corresponds in its function substantially tothe embodiment of FIG. 1. However, the opening means differs in that, inthis embodiment, a second clamping zone or station 17 is provided inplace of a cutting device 13, this clamping zone seizing the threadbehind the carding roll 12. The second clamping zone 17 is movablydisposed in the longitudinal direction of the thread, in a manner notshown in detail, so that it can be moved away from the carding roll 12,for example with the aid of a motor or a spring or the like. The openingof the thread in the area of the carding roll 12 leads to a weakening ofthe thread, so that it will break in this region upon movement of zone17. Accordingly, an opened up thread end can be produced which can bereturned into the spinning rotor 2 in the manner described inconjunction with FIG. ll. The cut off piece of thread 144 can then besucked up by nozzle 9.

in the embodiment of FIG. 3, a resilient trough 18 is provided in placeof blast nozzle 14 of FIG. 1. This trough 18 serves as the support forthe thread end to be combed out and is arranged in opposition to thecarding roll 12 on the other side of the thread end. This trough isformed of a curved leaf spring attached to the lower part of theclamping zone 11.

In the embodiments of FIGS. 1 and 3 wherein the thread is cut to lengthoutside of the immediate range of the carding rolls 12, it isadvantageous to dispose the carding rolls 12 on a shaft movable, duringthe combing out step, in the longitudinal direction of the thread, sothat the thread end is definitely reached (see arrow 12. depicting suchmovement in FIG. 3).

In the embodiment of FIG. .4, two comb-like carding elements 19 and 20are provided subsequently to the clamping zone 11. Elements 19 and 20receive the thread end between them and are driven in the direction ofthe thread end away from the clamping zone 11. The clamping zone 11, inthis embodiment, consists of a support 21 associated with a clamp 22,the latter contacting the thread 5 with its free end.

In the embodiment of FIG. 5, two identical means for carding purposesare arranged on both sides of the thread 5, in a similar manner as inthe embodiment of FIG. 4, so that a base member or support can beomitted. In this arrangement, two carding rolls 12 and 23 are provided,both of which are equipped with a trim constituted by teeth or pins160a. The directions of rotation of the two carding rolls 12 and 23 areselected so that both work on the thread end with their trims in thezone between them in a direction away from the clamping zone 11. Also,in this embodiment, it is advantageous to mount the two rotating cardingrolls 12 and 23 so that they can be moved together away from theclamping zone 11 toward the end of the thread 5, which latter is cut toa certain length by a cutter 13.

While We have shown and described several embodiments in accordance withthe present invention, it is understood that the same is not limitedthereto but is susceptible of numerous changes and modifications asknown to those skilled in the art, and We therefore do not wish to belimited to the details shown and described herein but intend to coverall such changes and modifications as are encompassed by the scope ofthe appended claims.

We claim:

1. Apparatus for piecing a thread end in an open-end spinning unithaving a spinning rotor with a ring of opened-up fibers comprising:

opening means including comb means for combing out the thread end,

and a device for returning the thread end into the spinning rotor aftercombing thereof by said comb means.

2. Apparatus for piecing a thread end in an open-end spinning unitaccording to claim 1, wherein a clamping device is provided for clampingsaid thread at a position spaced further from the extreme end of saidthread than is said comb means.

3. Apparatus for piecing a thread end in an open-end spinning unitaccording to claim 2, wherein said opening means includes means formoving said comb means toward the extreme end of said thread to effectsaid combing.

4. Apparatus for piecing a thread end in an open-end spinning unitaccording to claim 1, wherein a cutting device is provided for cuttingthe thread at a position spaced from said comb means.

5. Apparatus for piecing a thread end in an open-end spinning unitaccording to claim 3, wherein a cutting device is provided for cuttingsaid thread, said cutting device being disposed at the side of said combmeans opposite said clamping device.

6. Apparatus for piecing a thread end in an open-end spinning unitaccording to claim 1, wherein a pair of clamping devices are providedfor clamping said thread at respective opposite sides of said combmeans.

7. Apparatus for piecing a thread end in an open-end spinning unitaccording to claim 6, wherein the one of said clamping devices which isclosest to the extreme free end of said thread is movable in thelongitudinal direction of the thread for accommodating severing of thethread while being clamped by said clamping devices.

8. Apparatus for piecing a thread end in an open-end spinning unitaccording to claim 1, wherein a resilient support is arranged inopposition to said comb means for supporting said thread end duringcombing thereof.

9. Apparatus for piecing a thread end in an open-end spinning unitaccording to claim 3, wherein a resilient support is arranged inopposition to said comb means for supporting said thread end duringcombing thereof.

10. Apparatus for piecing a thread end in an openend spinning unitaccording to claim 5, wherein a resilient support is arranged inopposition to said comb means for supporting said thread end duringcombing thereof.

11. Apparatus for piecing a thread end in an openend spinning unitaccording to claim 7, wherein a resilient support is arranged inopposition to said comb means for supporting said thread end duringcombing thereof.

12. Apparatus for piecing a thread end in an openend spinning unitaccording to claim 1, wherein said comb means includes a pair of combingmembers disposed at opposite sides of the thread and movable in the samelongitudinal direction with respect to the thread during combingthereof.

13. Apparatus for piecing a thread end in an openend spinning unitaccording to claim 5, wherein said comb means includes a pair of combingmembers disposed at opposite sides of the thread and movable in the samelongitudinal direction with respect to the thread during combingthereof.

14. Apparatus for piecing a thread end in an openend spinning unitaccording to claim 7, wherein said comb means includes a pair of combingmembers disposed at opposite sides of the thread and movable in the samelongitudinal direction with respect to the thread during combingthereof.

15. Apparatus for piecing a thread end in an openend spinning unitaccording to claim 1, wherein a blowing means is arranged in oppositionto said comb means for supporting said thread end against said combmeans during combing thereof.

16. Apparatus for piecing a thread end in an openend spinning unitaccording to claim 5, wherein a blowing means is arranged in oppositionto said comb means for supporting said thread end against said combmeans during combing thereof.

17. Apparatus for piecing a thread end in an openend spinning unitaccording to claim 7, wherein a blowing means is arranged in oppositionto said comb means for supporting said thread end against said combmeans during combing thereof.

18. Apparatus for piecing a thread end in an openend spinning unitaccording to claim 1, wherein said comb means includes at least onerotatable carding roll and means for rotating said roll and moving saidroll toward the thread end.

19. Apparatus for piecing a thread end in an openend spinning unitaccording to claim 18, wherein the axis of said roll extends at rightangles to the longitudinal direction of said thread.

20. Apparatus for piecing a thread end in an openend spinning unitaccording to claim 5, wherein the axis of said roll extends at rightangles to the longitudinal direction of said thread.

21. Apparatus for piecing a thread end in an openend spinning unitaccording to claim 7, wherein the axis of said roll extends at rightangles to the longitudinal direction of said thread.

22. Apparatus for piecing a thread end in an openend spinning unitaccording to claim 8, wherein the axis of said roll extends at rightangles to the longitudinal direction of said thread.

23. Apparatus for piecing a thread end in an openend spinning unitaccording to claim 12, wherein the axis of said roll extends at rightangles to the longitudinal direction of said thread.

24. Apparatus for piecing a thread end in an openend spinning unitaccording to claim 15, wherein the axis of said roll extends at rightangles to the longitudinal direction of said thread.

25. Apparatus for piecing a thread end in an openend spinning unitaccording to claim 1, wherein said comb means includes at least onecomb-like element and means for displacing said comb-like element in thelongitudinal direction of the thread.

1. Apparatus for piecing a thread end in an open-end spinning unithaving a spinning rotor with a ring of opened-up fibers comprising:opening means including comb means for combing out the thread end, and adevice for returning the thread end into the spinning rotor aftercombing thereof by said comb means.
 2. Apparatus for piecing a threadend in an open-end spinning unit according to claim 1, wherein aclamping device is provided for clamping said thread at a positionspaced further from the extreme end of said thread than is said combmeans.
 3. Apparatus for piecing a thread end in an open-end spinningunit according to claim 2, wherein said opening means includes means formoving said comb means toward the extreme end of said thread to effectsaid combing.
 4. Apparatus for piecing a thread end in an open-endspinning unit according to claim 1, wherein a cutting device is providedfor cutting the thread at a position spaced from said comb means. 5.Apparatus for piecing a thread end in an open-end spinning unitaccording to claim 3, wherein a cutting device is provided for cuttingsaid thread, said cutting device being disposed at the side of said combmeans opposite said clamping device.
 6. Apparatus for piecing a threadend in an open-end spinning unit according to claim 1, wherein a pair ofclamping devices are provided for clamping said thread at respectiveopposite sides of said comb means.
 7. Apparatus for piecing a thread endin an open-end spinning unit according to claim 6, wherein the one ofsaid clamping devices which is closest to the extreme free end of saidthread is movable in the longitudinal direction of the thread foraccommodating severing of the thread while being clamped by saidclamping devices.
 8. Apparatus for piecing a thread end in an open-endspinning unit according to claim 1, wherein a resilient support isarranged in opposition to said comb means for supporting said thread endduring combing thereof.
 9. Apparatus for piecing a thread end in anopen-end spinning unit according to claim 3, wherein a resilient supportis arranged in opposition to said comb means for supporting said threadend during combing thereof.
 10. Apparatus for piecing a thread end in anopen-end spinning unit according to claim 5, wherein a resilient supportis arranged in opposition to said comb means for supporting said threadend during combing thereof.
 11. Apparatus for piecing a thread end in anopen-end spinning unit according to claim 7, wherein a resilient supportis arranged in opposition to said comb means for supporting said threadend during combing thereof.
 12. Apparatus for piecing a thread end in anopen-end spinning unit according to claim 1, wherein said comb meansincludes a pair of combing members disposed at opposite sides of thethread and movable in the same longitudinal direction with respect tothe thread during combing thereof.
 13. Apparatus for piecing a threadend in an open-end spinning unit according to claim 5, wherein said combmeans includes a pair of combing members disposed at opposite sides ofthe thread and movable in the same longitudinal direction with respectto the thread during combing thereof.
 14. Apparatus for piecing a threadend in an open-end spinning unit according to claim 7, wherein said combmeans includes a pair of combing members disposed at opposite sides ofthe thread and movable in the same longitudinal direction with respectto the thread during combing thereof.
 15. Apparatus for piecing a threadend in an open-end spinning unit according to claim 1, wherein a blowingmeans is arranged in opposition to said comb means for supporting saidthread end against said comb means during combing thereof.
 16. Apparatusfor piecing a thread end in an open-end spinning unit according to claim5, wherein a blowing means is arranged in opposition to said comb meansfor supporting said thread end against said comb means during combingthereof.
 17. Apparatus for piecing a thread end in an open-end spinningunit according to claim 7, wherein a blowing means is arranged inopposition to said comb means for supporting said thread end againstsaid comb means during combing thereof.
 18. Apparatus for piecing athread end in an open-end spinning unit according to claim 1, whereinsaid comb means includes at least one rotatable carding roll and meansfor rotating said roll and moving said roll toward the thread end. 19.Apparatus for piecing a thread end in an open-end spinning unitaccording to claim 18, wherein the axis of said roll extends at rightangles to the longitudinal direction of said thread.
 20. Apparatus forpiecing a thread end in an open-end spinning unit according to claim 5,wherein the axis of said roll extends at right angles to thelongitudinal direction of said thread.
 21. Apparatus for piecing athread end in an open-end spinning unit according to claim 7, whereinthe axis of said roll extends at right angles to the longitudinaldirection of said thread.
 22. Apparatus for piecing a thread end in anopen-end spinning unit according to claim 8, wherein the axis of saidroll extends at right angles to the longitudinal direction of saidthread.
 23. Apparatus for piecing a thread end in an open-end spinningunit according to claim 12, wherein the axis of said roll extends atright angles to the longitudinal direction of said thread.
 24. Apparatusfor piecing a thread end in an open-end spinning unit according to claim15, wherein the axis of said roll extends at right angles to thelongitudinal direction of said thread.
 25. Apparatus for piecing athread end in an open-end spinning unit according to claim 1, whereinsaid comb means includes at least one comb-like element and means fordisplacing said comb-like element in the longitudinal direction of thethread.